Pyridylaldehyde (PyAL) groups were bound onto the surface of crosslinked polystyrene (CPS) microspheres via quaternization between 4-pyridylaldehyde and chloromethyl groups of chloromethylated crosslinked polystyrene (CMCPS) microspheres, obtaining the modified microspheres PyAL-CPS. Subsequently,
synchronous synthesis and immobilization of pyridylporphyrin on CPS microspheres were successfully realized using
4-pyridylaldehyde, pyrrole and the modified microspheres
PyAL-CPS as the co-reactants via the Adler reaction between solid-liquid phases, resulting in functional microspheres PyP-CPS, on which pyridylporphyrin (PyP) was immobilized. The microspheres PyP-CPS were then allowed to react with
methyl iodide, and PyP was transformed to N-methyl pyridyl porphyrin (MPyP) iodide, leading to the formation of MPyP-CPS microspheres, on which cationic porphyrin was immobilized. Finally, the solid catalyst CoMPyP-CPS, on which cationic cobalt porphyrin was immobilized, was prepared through the coordination reaction between MPyP-CPS microspheres and cobalt salt. The effects of the main factors on the synchronous synthesis and immobilization of pyridylporphyrin on CPS microspheres were examined, and the catalytic performance of the solid catalyst CoMPyP-CPS in the oxidation of ethylbenzene by molecular oxygen was investigated mainly. Besides, the catalytic character of the composite catalyst CPW, which was prepared by association of CoMPyP-CPS (C) and phospho-tungstic(PW)heteropoly acid, was also investigated. The results show that the synchronous synthesis and immobilization of pyridylporphyrin on CPS microspheres can be favourably carried out using PyAL-CPS microspheres, 4-pyridylaldehyde, and pyrrole in the solution as co-reactants via the Adler reaction between solid-liquid phases. The immobilized cationic cobaltporphyrin catalyst CoMPyP-CPS has excellent catalytic performance in the oxidation of ethylbenzene by molecular oxygen, and the composite catalyst CPW possesses much higher catalytic activity.
